Georgiana F. Aboko-Cole

Trypanosoma lewisi. Body weight gains and food consumption of riboflavin-deficient rats given living cells, cell homogenates and cell metabolic products

Abstract 1. 1. Riboflavin deficiency was studied in rats infected with Trypanosoma lewisi . 2. 2. Body weight gains in rats on complete, riboflavin-deficient or pair-fed control diets and given living cells or homogenate of T. lewisi showed significant increases over uninoculated controls. 3. 3. Irrespective of dietary group, animals receiving living cells or homogenate of T. lewisi ate more food than the control animals beginning 12 days after inoculation. 4. 4. Regardless of diet, no differences in weight gain or food consumption were seen in animals inoculated with physiological saline or metabolic products of T. lewisi when compared with uninoculated controls.

Effect of malnutrition on susceptibility of mice to Trypanosoma musculi: Vitamin A-deficiency

SummaryVitamin A-deficiency was studied in mice infected with Trypanosoma musculi.Irrespective of diet, trypomastigotes (trypanosomes) appeared in peripheral tail blood of all inoculated mice after 6-day incubation periods. On the average, vitamin A-deficient mice had parasitemias about 10 times greater than animals fed a complete diet and 8 times pair-fed controls. Parasitemias lasted longer in vitamin-deficient hosts, and reached a maximum five days later than those from control hosts.The action of the antibody which inhibits reproduction of the trypomastigotes was delayed five days in vitamin-deficient mice; in pair-fed animals ablastic action occurred slightly earlier than in normal control animals. The action of the terminal lytic antibody was delayed by 6 days in metabolically deficient mice than in normal controls and by 4 days in pair-fed controls.Body weight gains in mice on complete, vitamin A-deficient or pair-fed control diets and given living cells or homogenate of T. musculi showed significant increases over uninoculated controls. Irrespective of dietary group, animals receiving living cells or homogenate of T. musculi ate more food than the control animals beginning 10 days after inoculation. Regardless of diet, no differences in weight gain or food consumption were seen in animals inoculated with physiological saline or metabolic products of T. musculi when compared with uninoculated controls.

Comparative metabolic activity of brain slices of rats infected with a pathogenic and a non-pathogenic trypanosome evidenced by cell population and respiratory activity

SummarySix experiments were performed to compare metabolic activity of brain slices of rats infected with Trypanosoma rhodesiense and Trypanosoma lewisi, “E” strain. For each parasite, rats were divided into five groups: — group A — inoculated with 100 living cells of the trypanosome; group B — inoculated with the metabolic products of the trypanosome; group C — inoculated with the homogenate of the trypanosome; group D — inoculated with normal physiological saline; group E — uninoculated.Oxygen consumption of brain slices was measured with Warburg respirometers, using 100 mg samples of brain slices in 15 ml flasks.Five rats from group A were reserved to examine development of parasitemia in peripheral blood. The number of trypanosomes was estimated by hemacytometer counts.Brain slices of rats inoculated with living cells of T. rhodesiense showed a 68% to 354% increase in oxygen consumption; those of rats inoculated with the homogenate of T. rhodesiense showed an increase of 6% to 345%. Brain slices of rats inoculated with living cells and homogenate of T. lewisi showed an increase of 4% to 425% and 2% to 312%, respectively.There were no statistically significant differences between respiratory rates of brain slices of rats that were inoculated with trypanosome metabolic products, saline and uninoculated controls.In rats inoculated with T. rhodesiense, density of parasitemia sharply increased from day 2 to 7. Death occurred on day 7. In rats inoculated with T. lewisi, parasitemia steadily increased from day 2 to 14, then gradually decreased from day 15 to 30, after which trypanosomes disappeared from the blood.

Iron metabolism in Trypanosoma lewisi infection: Serum iron and serum iron-binding capacity

SummaryProgressive changes in iron levels, total iron binding capacity and hematocrit values in sera of rats infected with Trypanosoma lewisi are described. The host dietary group were: (1) complete or full complement; (2) iron-deficient, and (3) pair-fed or calorically restricted.The hematocrit values of T. lewisi-infected rats given the various diets were not significantly different from those of the controls.The decrease in total iron binding capacity (TIBC) of rats inoculated with T. lewisi and fed complete and pair-fed diets ranged up to 15% over uninfected controls. TIBC levels in rats fed an iron-deficient diet and inoculated with T. lewisi ranged up to 32% over uninfected controls. TIBC levels of deficient infected rats were significantly different from the controls from day 90 of infection to the end of the observation period.Serum iron (SI) values of non-infected rats regardless of dietary regimen showed significantly higher values than T. lewisi-infected animals between days 95 and 120. The average SI value, for this period, in adequately fed control rats was 204±7 μg/100 ml as compared to 172±5 μg/100 for trypanosome-infected rats. SI levels of rats on a pair-fed diet and infected with T. lewisi decreased to 17% over uninfected controls. SI levels of animals on an iron-deficient diet and infected with T. lewisi decreased up to 76% over uninfected controls.

Trypanosoma lewisi: Body weight gains and food consumption of folate-deficient rats

Abstract 1. 1. Boby-weight gains and food consumption were studied in folate-deficient rats infected with Trypanosoma lewisi . 2. 2. Body-weight gains in infected rats, inoculated on Day 21, and fed complete diets showed a 2–64% increase over uninfected rats; those of infected rats fed a folate-deficient diet showed an increase of 1%–60%. 3. 3. Body-weight gains in infected rats, inoculated on Day 56, and fed complete, pair-fed and deficient diets ranged up to 44%, 47% and 27% respectively. 4. 4. Irrespective of diet or day of inoculation, infected rats showed statistically significant differences in food intake when compared with uninfected controls.

Trypanosoma lewisi: Cell populations and antibody formation in riboflavin deficient rats

SummaryThe influence of riboflavin deficiency on severity and duration of parasitemia was studied in Trypanosoma lewisi infected rats.The host dietary groups were: (1) complete or full complement; (2) riboflavin-deficient, and (3) pair-fed or calorically restricted. In all dietary groups, trypomastigotes appeared in peripheral tail blood of all inoculated rats after 7-day incubation periods. Riboflavin-deficient rats and pair-fed controls rats showed greater numbers of parasites than control-diet rats throughout the infection. The maximum parasitemia was on day 14 in control-diet rats; day 16 in riboflavin-deficient rats, and day 14 in pair-fed control rats. Parasitemia in riboflavin-deficient animals lasted 4 or more days longer than in the other two dietary groups.The average coefficients of variation in body length of trypomastigotes indicated that the formation of the reproduction inhibiting antibody (ablastin) was delayed seven days in riboflavin-deficient animals as compared with that in pair-fed and normal control animals.

Trypanosoma lewisi, Trypanosoma rhodesiense: mitotic activity in normal and folic acid deficient rats.

SummaryTen experiments were performed to compare mitotic activity in livers of rats infected with Trypanosoma rhodesiense and Trypanosoma lewisi.The host dietary groups were: (1) complete or full complement; (2) folic acid deficient, and (3) pair-fed or calorically restricted.Liver mitotic counts of T. lewisi-infected rats fed complete and pair-fed control diets showed a high degree of significance over that of control rats. From days 35 to 55, liver mitotic counts of T. lewisi-infected rats deficient in folic acid showed an average of 16±2 mitotic phases as compared to 9±2 for livers of uninfected animals.Liver mitotic counts of T. rhodesiense-infected and non-infected rats fed complete and pair-fed control diets showed that there were essentially no differences in the mitotic counts from that seen in liver from control, uninfected animals. On day 25 (day 5 of infection), folic acid-deficient infected rats showed a significantly higher number of dividing cells than the controls.Folate was measured in isolated, washed T. lewisi and T. rhodesiense cells. T. lewisi and T. rhodesiense contained 9.6 ng folate per 108 cells and 6.2 ng of folate per 108 cells respectively.Metabolic products of T. lewisi contained an average of 0.51 ng of folate per 108 trypanosomes. T. rhodesiense metabolic products contained 0.3 ng of folate per 108 trypanosomes.

Interaction of nutrition and infection:Trypanosoma lewisi, folic acid levels in sera and tissues of normal and folic acid-deficient rats

SummaryProgressive changes in folic acid levels in sera and tissues of rats infected withTrypanosoma lewisi are described. The host dietary groups were: (1) complete or full complement; (2) folic acid-deficient, and (3) pair-fed or calorically restrieted.Serum folate values of rats on a folic acid complete diet and pair-fed diet and inoculated on Day 21, showed significantly higher values than the controls between Days 35 and 45. The average serum folate values in adequately fed control rats was 16±3 ng/ml as opposed to 20±3 ng/ml for trypanosome-infected rats. Animals inoculated on Day 56 had higher folate values than control rats from Day 65 to Day 80. Serum folate content of deficient rats infected on Days 21 and 56 was significantly higher than the controls on Days 30 to 60 and 60 to 100, respectively.The livers of rats fed a folic complete and a pair-fed diet and inoculated on Days 21 and 56 withT. lewisi showed no significant difference in folate content when compared with the uninfected rats.Livers of folic acid-deficient rats infected withT. lewisi on Days 21 and 56 showed statistically significant increases over the controls from the 10th day of infection. Infected animals had 200% more folate than controls.Irrespective of diet and time of inoculation (Day 21 or 56), the folic acid content of brains and spinal, cords of rats infected withT. lewisi were not significantly different from that of the controls.

Trypanosoma rhodesiense: Folate levels in sera and tissues of normal and folic acid-deficient rats

SummaryAn experimental model composed of the folic acid deficient Sprague-Dawley rat and Trypanosoma rhodesiense was used to study folate levels in sera and tissues.Serum folate levels in well fed rats inoculated on Day 21 averaged 21±3 ng/ml; well feed normal rats averaged 18±4 ng/ml. In rats given the pair-fed control diet, serum folate levels averaged 17.2±4 ng/ml for trypanosome-free animals and 20.2±3 ng/ml for infected ones. In rats given the folic acid-deficient diet, serum folate levels averaged 8.6±2 ng/ml for noninfected control animals and 9.3±2 ng/ml for trypanosome-infected ones.Regardless of diet, the infected animals inoculated on Day 56 had higher serum folate levels over the controls on the last day of observation (Day 5 of infection).Livers from rats fed complete and pair-fed diets and inoculated on Day 21 showed no significant differences in folate content when compared to control animals. However, livers of rats on a deficient diet showed significantly more folate when compared with uninfected controls, reaching a maximum of 362% at Day 25.Liver folate levels of rats (regardless of the dietary regimen) inoculated on Day 56 showed significantly higher values than the controls on Day 60.Irrespective of the time of inoculation or diet, brain and spinal cord of T. rhodesiense-infected rats had significantly higher folate values than their controls on Day 5 of infection. The folate level of the brain and spinal cord, at this time, ranged up to 58 and 107% respectively.